By means of transmit precoding and receive combining, a multiple input multiple output (MIMO) system can obtain a diversity gain and an array gain. A system using precoding may be represented as:y=HVs+n 
where y is a received signal vector, H is a channel matrix, V is a precoding matrix, s is a transmitted symbol vector, and n is an interference and noise vector.
Optimal precoding usually requires that a transmitter completely knows channel state information (CSI). A commonly-used method is: user equipment (User Equipment, UE for short) quantizes instantaneous CSI, and sends a feedback to a base station.
In an existing long term evolution (LTE) R8-R11 (Release 8-11) system, CSI fed back by UE includes rank indicator (RI) information, precoding matrix indicator (PMI) information, channel quality indicator (CQI) information, and the like, where the RI and the PMI respectively indicate a quantity of used layers and a precoding matrix. A set of a used precoding matrix is generally referred to as a codebook, where each precoding matrix is a code word in the codebook.
In order to reduce system costs and meanwhile achieve higher requirements on a system capacity and coverage, an active antenna system (AAS) has been widely studied. Compared with an existing base station antenna that has only a capability of controlling a beam orientation in a horizontal direction, the AAS can provide a capability of controlling a beam orientation both in a horizontal direction and in a perpendicular direction, and meanwhile, has a capability of controlling a beam shape to control power distribution in space. However, in the prior art, a precoding matrix fed back by UE to a node device cannot effectively control a beam, especially a beam shape and a beam orientation, in a horizontal direction and a perpendicular direction at the same time.